Earth drilling auger



May 14, 1968 .J. P. WATTS EARTH DRILLING AUGER Filed June 28, 1966VII/TV R mm A ww w.

R S E M A IU ATTORNEY United States Patent Office 3,382,935 Patented May14, 1968 3,382,935 EARTH DRILLING AUGER James P. Watts, 6930 E. Pinchot,Scottsdale, Ariz. 85251 Filed June 28, 1966, Ser. No. 561,114 1 Claim.(Cl. 175313) This invention relates to improved earth drilling augers.

More particularly, the invention concerns earth drilling augersespecially adapted to drilling in wet or loosely packed earth.

In a particular aspect, the invention concerns an improved earthdrilling auger which is capable of boring a cylindrical hole ofsubstantially uniform cross-section.

In boring holes in the earth for the purpose of pouring concretefoundation piers, such as are required for heavy building constructionand the like, it is highly desired that the bored holes be ofsubstantially uniform crosssection. In this way, the building contractorcan pour only the amount of concrete required to achieve the minimumnecessary structural strength and avoid waste of concrete due toirregularly shaped holes.

Holes bored by the use of apparatus commonly known and used in the priorart were often irregularly shaped due to the fact that the walls tendedto collapse into the hole as the drilling auger was removed forcleaning. The collapse of the walls was primarily due to suction effectscreated when the auger was lifted from the hole. This problem wasespecially acute in drilling wet soil as the mud encountered functionedas an effective air seal, thus increasing the vacuum created in the holewhen the auger was lifted.

It would be highly advantageous to provide a drilling auger especiallyadapted to prevent collapse of the walls of the bore hole when the augeris lifted from the hole. In this way, the cross-section of the hole ismaintained substantially uniform along its length and the amount ofconcrete required to fill the hole is limited to just that required toproduce a pier having the required structural strength.

Accordingly, it is a principal object of the present invention toprovide an improved drilling auger;

Another object of the invention is the provision of a drilling augerespecially adapted for use when boring holes in wet or moist earth;

A further object of the invention is the provision of an improveddrilling auger assembly which is conveniently and economically emptiedof earth, mud, etc., during the drilling operation;

Yet another object of the invention is the provision of an improveddrilling auger assembly which is economically and convenientlyfabricated and which is adapted for easy maintenance;

These and other, further, and more specific objects and advantages ofthe invention will become apparent from the following detaileddescription of the invention taken in conjunction with the drawings inwhich:

FIG. 1 is a sectional view of an anger assembly embodying the presentinvention and in which the presently preferred embodiment is shown anddescribed;

FIG. 2 is a partial perspective view of the auger assembly of FIG. 1showing the hinged cover member displaced from its normally closedposition;

FIG. 3 is a perspective view illustrating the bottom portion of theauger assembly and showing the arrangement and operative relationship ofthe various cutter elements.

Briefly, in accordance with my invention, I provide an earth drillingauger comprising a rotatable central vertical shaft having a cutter barextending radially outwardly from the shaft adjacent the lower endthereof, a spiral screw flight carried by the shaft and extendingupwardly from the cutter bar, a cylindrical casing coaxially disposedaround and enclosing the screw flight, the interior vertical surfaces ofthe casing slidably frictionally engaging the periphery of the screwflight, cutter elements carried by the lower edge of the casing andextending outwardly therefrom, and a cover member normally closing thetop of the cylindrical casing, the cover member having a perforatedhinged portion adapted to be displaced from the normally closed positionof the cover.

Referring now to the drawings, in which like numerals identify the sameelements in the various figures, FIG. 1 illustrates an auger assemblyembodying the present invention and shows a rotatable central verticalshaft 1 having a cutter bar 2 extending radially outwardly from theshaft adjacent the lower end 3 thereof. A spiral screw flight 4 iscarried by the shaft 1 and extends upwardly from the cutter bar 2. Acylindrical casing 5 is disposed coaxially with the shaft 1 and thescrew flight 4, enclosing the screw flight. The interior verticalsurfaces 5a of the casing 5 slidably frictionally engage the periphery4a of the screw flight forming points of contact 4b between the interiorsurface 5a of the casing 5 and the periphery 4a of the screw flight 4.These points of contact 4b cause the casing 5 to rotate more or lessconcurrently with the shaft 1 and screw flight 4, but provide forslippage between the casing 5 and the screw flight 4, providing afreewheeling effect.

The casing 5 is provided with cutter elements 6 extending radiallyoutwardly from the casing a short distance. These cutter elements'provide a clearance between the exterior of the casing 5 and the sideof the bore hole permitting passage of air and water between the casing5 and the bore hole wall. This clearance reduces to a minimum the vacuumcreated in the bottom of the bore hole when the auger assembly is liftedfrom the hole. The bottom of the shaft 1 is provided with a pilot auger7 which positions the auger laterally within the bore hole and providesan initial entry into the earth to be drilled. The top of the verticalshaft 1 is provided with suitable means for connecting the auger to therotating driving shaft of a drilling rig (not shown). In the device ofFIG. 1, the means for connecting the auger to the drilling rig shaftcomprises a female socket 8 having a square cross section and suitableholes 8a for inserting keys to lock the apparatus to the bottom of thedrilling rig shaft.

The casing 5 is provided with a cover member 9 which is provided with acentral aperture 9n, within which the vertical shaft 1 rotates freely.Vertical movement of the casing 5 is limited by a collar 91) extendingupwardly from the central aperture 911 and bearing upon the lowershoulder 3b of the socket 8.

Referring to FIG. 2, it will be seen that the cover memher 9 is providedwith a perforated hinged portion 9c which is adapted to be displaced, asshown in FIG. 2, from its normally closed position. The hinged portionmay be conveniently secured in its normally closed position by means ofa latch assembly comprising a swing C washer 10 which engages stud 11located on the stationary portion of the cover 9.

In operation, the improved drilling auger operates as follows.

Downward pressure in the direction of the arrow A of FIG. 1 is exertedby the drilling rig shaft seated in the socket 8 and the device isrotated in the direction of the arrow B of FIG. 2. The pilot auger 7initially penetrates the earth to provide lateral stability for the maindrilling elements. The cutter bar 2 engages the earth and displaces itupwardly onto the spiral screw flight 4 which carries the displaced andcomminuted earth, mud, etc., upwardly into the interior of the casing 5.Frictional engagement between the casing 5 and the periphery 4a of thescrew flight 4 causes rotation of the casing 5 in the same direction.The cutter elements 6 located on the bottom edge of the casing 5 enlargethe hole slightly to provide clearance between the casing 5 and thewalls of the bore hole. When the casing 5 is filled with earth, mud,etc., as evidenced by discharge of some of the material through theperforations 9d in the cover member 9, the entire assembly is withdrawnfrom the bore hole and, still connected to the rotatable shaft of thedrilling rig, it is positioned at a location remote from the bore holepreparatory to discharging the contents of the casing.

The contents of the casing are dischar ed by immobilizing the casingfrom rotation. This can be accomplished in any suitable manner, such as,for example, by placing several turns of a cable or a rope around thecasing or by clamping the casing to some stationary object. The hingedportion of the cover member is then opened and the anger is rotated inthe same direction as when drilling, thereby discharging the contents ofthe casing through the opened cover member. After the casing is emptied,the cover member is closed and latched, the apparatus is reinserted intothe bore hole and the operation is repeated.

The apparatus of the present invention is therefore to be clearlydistinguished from prior art augers employing a casing which is afiixedto the auger and which must be removed from the auger, as by liftingclear of the screw flight, before the discharging operation can becommenced.

Various changes in the devices chosen for purposes of illustration inthe drawings will readily occur to persons skilled in the art havingregard for the disclosure hereof. To the extent that such modificationsand variations do not depart from the spirit of the invention, they areintended to be included within the scope thereof which is not limited tothe devices specifically illustrated in the drawings but, rather, onlyby a just interpretation of the following claim.

Having fully described the invention in such manner as to enable thoseskilled in the art to understand and practice the same, the inventionclaimed is:

1. An earth drilling auger especially adapted for boring holes in wetsoil comprising:

(a) a rotatable central vertical shaft;

(0) a cutter bar extending radially outwardly from said shaft adjacentthe lower end thereof;

(0) a spiral screw flight carried by said shaft and extending upwardlyfrom said cutter bar;

(d) a cylindrical casing coaxially disposed around and enclosing saidscrew flight, the interior vertical surfaces of said casing slidablyfrictionally engaging the peripheiy of said screw flight;

(e) cutter elements carried by the lower edge of said casing andextending outwardly therefrom;

(f) a cover member normally closing the top of said cylindrical casing,said cover member having a perforated hinged portion adapted to bedisplaced from said normally closed position.

References Cited UNITED STATES PATENTS 1,519,132 12/1924 Grothe 3131,616,666 2/1927 Nebergall 175-323 FOREIGN PATENTS 123,009 1/ 1901Germany.

CHARLES E. OCONNELL, Primary Examiner.

N. C. BYERS, Examiner.

1. AN EARTH DRILLING AUGER ESPECIALLY ADAPTED FOR BORING HOLES IN WETSOIL COMPRISING: (A) A ROTATABLE CENTRAL VERTICAL SHAFT; (B) A CUTTERBAR EXTENDING RADIALLY OUTWARDLY FROM SAID SHAFT ADJACENT THE LOWER ENDTHEREOF; (C) A SPIRAL SCREW FLIGHT CARRIED BY SAID SHAFT AND EXTENDINGUPWARDLY FROM SAID CUTTER BAR; (D) A CYLINDRICAL CASING COAXIALLYDISPOSED AROUND AND ENCLOSING SAID SCREW FLIGHT, THE INTERIOR VERTICALSURFACES OF SAID CASING SLIDABLY FRICTIONALLY ENGAGING THE PERIPHERY OFSAID SCREW FLIGHT; (E) CUTTER ELEMENTS CARRIED BY THE LOWER EDGE OF SAIDCASING AND EXTENDING OUTWARDLY THEREFROM; (F) A COVER MEMBER NORMALLYCLOSING THE TOP OF SAID CYLINDRICAL CASING, SAID COVER MEMBER HAVING APERFORATED HINGED PORTION ADAPTED TO BE DISPLACED FROM SAID NORMALLYCLOSED POSITION.